1. Field of the Invention
This invention relates to a fractionation vessel having physical separation of a fractionation column feed vapor inlet contacting zone from a lower temperature liquid pool immediately below it in order to avoid condensation and absorption by the liquid pool of valuable components in the feed product vapors. The invention is directed to a fractionator and a method which isolates the product vapors from the cooler liquid pool. In addition to desired thermal separation, the invention provides more rapid and uniform quenching of hot liquid entering the bottoms hold-up pool plus facilitates lower temperature operation of the pool to minimize thermal degradation of the bottoms liquid.
2. Information Disclosure Statement
The following patents are representative of the state-of-the-art of fractionation:
U.S. Pat. No. 2,235,329 issued to E. A. Ocon on Mar. 18, 1941 is directed to a method and apparatus for treating a plurality of heavy hydro-carbon oils for subsequent cracking utilizing a fractionation tower which is typical of the prior art and does not utilize a separation tray and downpipe as is used in the present invention.
U.S. Pat. No. 3,133,014 issued to W. J. Cross, Jr. on May 12, 1964 describes a quench system for synthetic crude wherein a fractionation vessel utilizes an improved arrangement for introduction of quench liquid. A separation tray is not used as in the present invention.
U.S. Pat. No. 4,714,542 issued to W. Lockett, Jr. on Dec. 22, 1987 relates to a distillation vapor and feed mixing and subsequent separation process and apparatus which involves the introduction of a vaporizing liquid feed into a flash zone via a tangential nozzle into a mixing and separation chamber which directs the feed into a circumferential path to enhance mixing, and the redirection of rising vapors from the distillation below the flash zone by baffling these vapors into the chamber inlet. The rising vapors are inspirated by the high velocity feed at the inlet side of the chamber and intimate contact and mixing of the rising vapors with the vaporizing feed are enhanced by creating a spinning action. Preferably, the chamber runs peripherally and slightly downward along the inside of wall of the distillation column along an arc no greater than 360.degree.. Alternatively, the mixing section of the mixing and separation chamber may be located outside of the distillation tower and the feed, passing through a jet ejector would inspirate the rising vapors. Increasing contacting and mixing efficiency in a distillation flash zone increases the yield of more valuable overhead product for the same energy input or permits lower energy input for constant separation between overheads and bottom in the flash zone.
Notwithstanding the above-cited prior art, the present invention is neither taught nor rendered obvious thereby.